Stool test

A stool test examines the stool (poop). Stool tests are useful for looking at problems in the gastrointestinal (GI) tract.

Why a stool test is done

A stool test may be done to check for:

  • bleeding inside the GI tract
  • infection from bacteria, viruses or fungus
  • parasites
  • digestive conditions

Screening for colorectal cancer uses stool tests to check for bleeding inside the GI tract. Find out more about screening for colorectal cancer.

Types of stool tests

There are several types of stool tests. The type of stool test used depends on why the test is being done and what the doctor is looking for.

  • A gFOBT (guaiac-based fecal occult blood test) uses a chemical reaction on a paper card to find traces of blood in the stool that you can’t see.
  • A FIT (fecal immunochemical test) uses specific antibodies for human blood to find traces of blood in the stool that you can’t see.
  • A stool culture looks for bacteria that are not normally found in the GI tract.
  • Stool fat testing looks for extra fat in the stool to see if the body is having trouble absorbing fat from food.

How a stool test is done

A stool sample is usually collected at home. Wear latex gloves and follow your doctor’s instructions for collecting and saving the stool sample.

Different methods can be used to collect the stool, including:

  • using a hat-shaped plastic container placed over the toilet bowl
  • placing plastic wrap loosely over the toilet bowl
  • lining a diaper with plastic wrap (for infants or toddlers)

If urine (pee) is mixed with the stool or if the stool touches the inside of the toilet bowl, another sample will have to be collected.

The stool sample will be looked at under a microscope at the lab.

What the results mean

Normal stool usually appears brown, soft and well-formed in consistency. It does not contain blood, mucus, pus or harmful micro-organisms.

Abnormal results from different types of tests may be caused by:

  • inflammation of the intestine, such as ulcerative colitis or Crohn’s disease
  • hemorrhoids (enlarged, swollen veins inside or outside of the anus)
  • polyps (growths attached to the colon or rectum)
  • anal fissures (thin tears in the lining of the anus)
  • peptic ulcers
  • infection
  • parasites
  • digestive conditions, such as not absorbing certain fats or other nutrients
  • use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs)
  • cancer

What happens if the results are abnormal

Your doctor may recommend more tests, procedures, follow-up care or treatment.

Special considerations for children

Preparing children before a test or procedure can help lower their anxiety, increase their cooperation and develop their coping skills. This includes explaining to children what will happen during the test, such as what they will see, feel and hear.

Preparing a child for a stool test depends on the age and experience of the child. Find out more about helping your child cope with tests and treatments.

Expert review and references

  • American Cancer Society . Colorectal Cancer . 2018 :
  • Stool tests for colorectal cancer . British Columbia Ministry of Health . HealthLink BC . 2018 :
  • Fischbach FT, Fischbach MA. Fischbach's A Manual of Laboratory and Diagnostic Tests. 10th ed. Wolters Kluwer; 2018.
  • Wilkes GM . Colon, rectal, and anal cancers. Yarbro CH, Wujcki D, Holmes Gobel B, (eds.). Cancer Nursing: Principles and Practice. 8th ed. Burlington, MA: Jones and Bartlett Learning; 2018: 51: 1423 - 1485.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

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